In conventional HMDs, a reflective array is utilized to reflect images to an eye of a user wearing the HMD. These reflective arrays typically include a two-dimensional reflector such as a corner cube. In general, a two-dimensional reflective array reflects the image back to the point of origin in both a horizontal axis and a vertical axis.
In order to fold the image away from the point of origin (i.e. the source), conventional HMDs implement a beam splitter which allows the reflected image to pass through the splitter and onto the eye of the user. This additional beam splitter results in a more complicated, bulky and expensive HMD.